#include <bits/stdc++.h>
using namespace std;

#define int int64_t
#define endl "\n"

using PII = pair<int, int>;
using TII = tuple<int, int, int>;
template<class T> using V = vector<T>;
using i64 = long long;
using i128 = __int128;
using u64 = unsigned long long;

#define FOR(i, a, b) for (int i = (int)(a); i <= (int)(b); i++)
#define FOR2(i, a, b, c) for (int i = (int)(a); i <= (int)(b); i += c)
#define FORD(i, b, a) for (int i = (int)(a); i >= (int)(b); i--)
#define FORD2(i, b, a, c) for (int i = (int)(a); i >= (int)(b); i -= c)
#define ALL(a) a.begin(), a.end()
#define RALL(a) a.rbegin(), a.rend()
#define lowbit(x) ((x) & (-x))
#define RE return;
#define Yes cout << "Yes" << endl;
#define YES cout << "YES" << endl;
#define No cout << "No" << endl;
#define NO cout << "NO" << endl;
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define sz(x) (int)(x).size()

void solve() {
    int n;
    cin >> n;
    V<int> w(n + 1, 0);
    FOR(i, 1, n) cin >> w[i];

    FOR(i, 2, n) {
        if (abs(w[i] - w[i - 1]) > 1) {
            cout << 0 << endl;
            RE;
        }
    }

    int ans = 0;

    auto check = [&](char x) {
        string s(n + 1, ' ');
        s[1] = x;
        FOR(i, 2, n) {
            if (w[i] - w[i - 1] == 1) {
                if (s[i - 1] == 'L')
                    s[i] = 'L';
                else {
                    return 0;
                }
            } else if (w[i] == w[i - 1]) {
                if (s[i - 1] == 'L')
                    s[i] = 'R';
                else {
                    s[i] = 'L';
                }
            } else {
                if (s[i - 1] == 'R')
                    s[i] = 'R';
                else
                    return 0;
            }
        }

        int cl = 0, cr = 0;
        FOR(i, 1, n) {
            if (s[i] == 'R') cr++;
        }

        FOR(i, 1, n) {
            if (s[i] == 'R') cr--;
            if (w[i] != (cr + cl + 1)) {
                return 0;
            }
            if (s[i] == 'L') cl++;
        }

        return 1;
    };

    if (check('L')) ans++;
    if (check('R')) ans++;

    cout << ans << endl;
}

signed main() {
    int Task = 1;

    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> Task;
    while (Task--) {
        solve();
    }

    return 0;
}
